/**
 * \file common.h
 *
 * \brief Utility macros for internal use in the library
 */
/*
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#ifndef MBEDTLS_LIBRARY_COMMON_H
#define MBEDTLS_LIBRARY_COMMON_H

#include "mbedtls/build_info.h"

#include <stdint.h>
#include <stddef.h>

/** Helper to define a function as static except when building invasive tests.
 *
 * If a function is only used inside its own source file and should be
 * declared `static` to allow the compiler to optimize for code size,
 * but that function has unit tests, define it with
 * ```
 * MBEDTLS_STATIC_TESTABLE int mbedtls_foo(...) { ... }
 * ```
 * and declare it in a header in the `library/` directory with
 * ```
 * #if defined(MBEDTLS_TEST_HOOKS)
 * int mbedtls_foo(...);
 * #endif
 * ```
 */
#if defined(MBEDTLS_TEST_HOOKS)
#define MBEDTLS_STATIC_TESTABLE
#else
#define MBEDTLS_STATIC_TESTABLE static
#endif

#if defined(MBEDTLS_TEST_HOOKS)
extern void (*mbedtls_test_hook_test_fail)( const char * test, int line, const char * file );
#define MBEDTLS_TEST_HOOK_TEST_ASSERT( TEST ) \
       do { \
            if( ( ! ( TEST ) ) && ( ( *mbedtls_test_hook_test_fail ) != NULL ) ) \
            { \
              ( *mbedtls_test_hook_test_fail )( #TEST, __LINE__, __FILE__ ); \
            } \
    } while( 0 )
#else
#define MBEDTLS_TEST_HOOK_TEST_ASSERT( TEST )
#endif /* defined(MBEDTLS_TEST_HOOKS) */

/** \def ARRAY_LENGTH
 * Return the number of elements of a static or stack array.
 *
 * \param array         A value of array (not pointer) type.
 *
 * \return The number of elements of the array.
 */
/* A correct implementation of ARRAY_LENGTH, but which silently gives
 * a nonsensical result if called with a pointer rather than an array. */
#define ARRAY_LENGTH_UNSAFE(array)            \
    (sizeof(array) / sizeof(*(array)))

#if defined(__GNUC__)
/* Test if arg and &(arg)[0] have the same type. This is true if arg is
 * an array but not if it's a pointer. */
#define IS_ARRAY_NOT_POINTER(arg)                                     \
    (!__builtin_types_compatible_p(__typeof__(arg),                \
                                   __typeof__(&(arg)[0])))
/* A compile-time constant with the value 0. If `const_expr` is not a
 * compile-time constant with a nonzero value, cause a compile-time error. */
#define STATIC_ASSERT_EXPR(const_expr)                                \
    (0 && sizeof(struct { unsigned int STATIC_ASSERT : 1 - 2 * !(const_expr); }))

/* Return the scalar value `value` (possibly promoted). This is a compile-time
 * constant if `value` is. `condition` must be a compile-time constant.
 * If `condition` is false, arrange to cause a compile-time error. */
#define STATIC_ASSERT_THEN_RETURN(condition, value)   \
    (STATIC_ASSERT_EXPR(condition) ? 0 : (value))

#define ARRAY_LENGTH(array)                                           \
    (STATIC_ASSERT_THEN_RETURN(IS_ARRAY_NOT_POINTER(array),         \
                               ARRAY_LENGTH_UNSAFE(array)))

#else
/* If we aren't sure the compiler supports our non-standard tricks,
 * fall back to the unsafe implementation. */
#define ARRAY_LENGTH(array) ARRAY_LENGTH_UNSAFE(array)
#endif
/** Allow library to access its structs' private members.
 *
 * Although structs defined in header files are publicly available,
 * their members are private and should not be accessed by the user.
 */
#define MBEDTLS_ALLOW_PRIVATE_ACCESS

/**
 * \brief       Securely zeroize a buffer then free it.
 *
 *              Similar to making consecutive calls to
 *              \c mbedtls_platform_zeroize() and \c mbedtls_free(), but has
 *              code size savings, and potential for optimisation in the future.
 *
 *              Guaranteed to be a no-op if \p buf is \c NULL and \p len is 0.
 *
 * \param buf   Buffer to be zeroized then freed.
 * \param len   Length of the buffer in bytes
 */
void mbedtls_zeroize_and_free(void *buf, size_t len);

/** Byte Reading Macros
 *
 * Given a multi-byte integer \p x, MBEDTLS_BYTE_n retrieves the n-th
 * byte from x, where byte 0 is the least significant byte.
 */
#define MBEDTLS_BYTE_0( x ) ( (uint8_t) (   ( x )         & 0xff ) )
#define MBEDTLS_BYTE_1( x ) ( (uint8_t) ( ( ( x ) >> 8  ) & 0xff ) )
#define MBEDTLS_BYTE_2( x ) ( (uint8_t) ( ( ( x ) >> 16 ) & 0xff ) )
#define MBEDTLS_BYTE_3( x ) ( (uint8_t) ( ( ( x ) >> 24 ) & 0xff ) )
#define MBEDTLS_BYTE_4( x ) ( (uint8_t) ( ( ( x ) >> 32 ) & 0xff ) )
#define MBEDTLS_BYTE_5( x ) ( (uint8_t) ( ( ( x ) >> 40 ) & 0xff ) )
#define MBEDTLS_BYTE_6( x ) ( (uint8_t) ( ( ( x ) >> 48 ) & 0xff ) )
#define MBEDTLS_BYTE_7( x ) ( (uint8_t) ( ( ( x ) >> 56 ) & 0xff ) )

/**
 * Get the unsigned 32 bits integer corresponding to four bytes in
 * big-endian order (MSB first).
 *
 * \param   data    Base address of the memory to get the four bytes from.
 * \param   offset  Offset from \p data of the first and most significant
 *                  byte of the four bytes to build the 32 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT32_BE
#define MBEDTLS_GET_UINT32_BE( data , offset )                  \
    (                                                           \
          ( (uint32_t) ( data )[( offset )    ] << 24 )         \
        | ( (uint32_t) ( data )[( offset ) + 1] << 16 )         \
        | ( (uint32_t) ( data )[( offset ) + 2] <<  8 )         \
        | ( (uint32_t) ( data )[( offset ) + 3]       )         \
    )
#endif

/**
 * Put in memory a 32 bits unsigned integer in big-endian order.
 *
 * \param   n       32 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 32
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the most significant
 *                  byte of the 32 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT32_BE
#define MBEDTLS_PUT_UINT32_BE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_3( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_2( n );             \
    ( data )[( offset ) + 2] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 3] = MBEDTLS_BYTE_0( n );             \
}
#endif

/**
 * Get the unsigned 32 bits integer corresponding to four bytes in
 * little-endian order (LSB first).
 *
 * \param   data    Base address of the memory to get the four bytes from.
 * \param   offset  Offset from \p data of the first and least significant
 *                  byte of the four bytes to build the 32 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT32_LE
#define MBEDTLS_GET_UINT32_LE( data, offset )                   \
    (                                                           \
          ( (uint32_t) ( data )[( offset )    ]       )         \
        | ( (uint32_t) ( data )[( offset ) + 1] <<  8 )         \
        | ( (uint32_t) ( data )[( offset ) + 2] << 16 )         \
        | ( (uint32_t) ( data )[( offset ) + 3] << 24 )         \
    )
#endif

/**
 * Put in memory a 32 bits unsigned integer in little-endian order.
 *
 * \param   n       32 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 32
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the least significant
 *                  byte of the 32 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT32_LE
#define MBEDTLS_PUT_UINT32_LE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_0( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 2] = MBEDTLS_BYTE_2( n );             \
    ( data )[( offset ) + 3] = MBEDTLS_BYTE_3( n );             \
}
#endif

/**
 * Get the unsigned 16 bits integer corresponding to two bytes in
 * little-endian order (LSB first).
 *
 * \param   data    Base address of the memory to get the two bytes from.
 * \param   offset  Offset from \p data of the first and least significant
 *                  byte of the two bytes to build the 16 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT16_LE
#define MBEDTLS_GET_UINT16_LE( data, offset )                   \
    (                                                           \
          ( (uint16_t) ( data )[( offset )    ]       )         \
        | ( (uint16_t) ( data )[( offset ) + 1] <<  8 )         \
    )
#endif

/**
 * Put in memory a 16 bits unsigned integer in little-endian order.
 *
 * \param   n       16 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 16
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the least significant
 *                  byte of the 16 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT16_LE
#define MBEDTLS_PUT_UINT16_LE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_0( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_1( n );             \
}
#endif

/**
 * Get the unsigned 16 bits integer corresponding to two bytes in
 * big-endian order (MSB first).
 *
 * \param   data    Base address of the memory to get the two bytes from.
 * \param   offset  Offset from \p data of the first and most significant
 *                  byte of the two bytes to build the 16 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT16_BE
#define MBEDTLS_GET_UINT16_BE( data, offset )                   \
    (                                                           \
          ( (uint16_t) ( data )[( offset )    ] << 8 )          \
        | ( (uint16_t) ( data )[( offset ) + 1]      )          \
    )
#endif

/**
 * Put in memory a 16 bits unsigned integer in big-endian order.
 *
 * \param   n       16 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 16
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the most significant
 *                  byte of the 16 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT16_BE
#define MBEDTLS_PUT_UINT16_BE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_0( n );             \
}
#endif

/**
 * Get the unsigned 24 bits integer corresponding to three bytes in
 * big-endian order (MSB first).
 *
 * \param   data    Base address of the memory to get the three bytes from.
 * \param   offset  Offset from \p data of the first and most significant
 *                  byte of the three bytes to build the 24 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT24_BE
#define MBEDTLS_GET_UINT24_BE( data , offset )                  \
    (                                                           \
          ( (uint32_t) ( data )[( offset )    ] << 16 )         \
        | ( (uint32_t) ( data )[( offset ) + 1] << 8  )         \
        | ( (uint32_t) ( data )[( offset ) + 2]       )         \
    )
#endif

/**
 * Put in memory a 24 bits unsigned integer in big-endian order.
 *
 * \param   n       24 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 24
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the most significant
 *                  byte of the 24 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT24_BE
#define MBEDTLS_PUT_UINT24_BE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_2( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 2] = MBEDTLS_BYTE_0( n );             \
}
#endif

/**
 * Get the unsigned 24 bits integer corresponding to three bytes in
 * little-endian order (LSB first).
 *
 * \param   data    Base address of the memory to get the three bytes from.
 * \param   offset  Offset from \p data of the first and least significant
 *                  byte of the three bytes to build the 24 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT24_LE
#define MBEDTLS_GET_UINT24_LE( data, offset )                   \
    (                                                           \
          ( (uint32_t) ( data )[( offset )    ]       )         \
        | ( (uint32_t) ( data )[( offset ) + 1] <<  8 )         \
        | ( (uint32_t) ( data )[( offset ) + 2] << 16 )         \
    )
#endif

/**
 * Put in memory a 24 bits unsigned integer in little-endian order.
 *
 * \param   n       24 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 24
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the least significant
 *                  byte of the 24 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT24_LE
#define MBEDTLS_PUT_UINT24_LE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_0( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 2] = MBEDTLS_BYTE_2( n );             \
}
#endif

/**
 * Get the unsigned 64 bits integer corresponding to eight bytes in
 * big-endian order (MSB first).
 *
 * \param   data    Base address of the memory to get the eight bytes from.
 * \param   offset  Offset from \p data of the first and most significant
 *                  byte of the eight bytes to build the 64 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT64_BE
#define MBEDTLS_GET_UINT64_BE( data, offset )                   \
    (                                                           \
          ( (uint64_t) ( data )[( offset )    ] << 56 )         \
        | ( (uint64_t) ( data )[( offset ) + 1] << 48 )         \
        | ( (uint64_t) ( data )[( offset ) + 2] << 40 )         \
        | ( (uint64_t) ( data )[( offset ) + 3] << 32 )         \
        | ( (uint64_t) ( data )[( offset ) + 4] << 24 )         \
        | ( (uint64_t) ( data )[( offset ) + 5] << 16 )         \
        | ( (uint64_t) ( data )[( offset ) + 6] <<  8 )         \
        | ( (uint64_t) ( data )[( offset ) + 7]       )         \
    )
#endif

/**
 * Put in memory a 64 bits unsigned integer in big-endian order.
 *
 * \param   n       64 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 64
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the most significant
 *                  byte of the 64 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT64_BE
#define MBEDTLS_PUT_UINT64_BE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_7( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_6( n );             \
    ( data )[( offset ) + 2] = MBEDTLS_BYTE_5( n );             \
    ( data )[( offset ) + 3] = MBEDTLS_BYTE_4( n );             \
    ( data )[( offset ) + 4] = MBEDTLS_BYTE_3( n );             \
    ( data )[( offset ) + 5] = MBEDTLS_BYTE_2( n );             \
    ( data )[( offset ) + 6] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 7] = MBEDTLS_BYTE_0( n );             \
}
#endif

/**
 * Get the unsigned 64 bits integer corresponding to eight bytes in
 * little-endian order (LSB first).
 *
 * \param   data    Base address of the memory to get the eight bytes from.
 * \param   offset  Offset from \p data of the first and least significant
 *                  byte of the eight bytes to build the 64 bits unsigned
 *                  integer from.
 */
#ifndef MBEDTLS_GET_UINT64_LE
#define MBEDTLS_GET_UINT64_LE( data, offset )                   \
    (                                                           \
          ( (uint64_t) ( data )[( offset ) + 7] << 56 )         \
        | ( (uint64_t) ( data )[( offset ) + 6] << 48 )         \
        | ( (uint64_t) ( data )[( offset ) + 5] << 40 )         \
        | ( (uint64_t) ( data )[( offset ) + 4] << 32 )         \
        | ( (uint64_t) ( data )[( offset ) + 3] << 24 )         \
        | ( (uint64_t) ( data )[( offset ) + 2] << 16 )         \
        | ( (uint64_t) ( data )[( offset ) + 1] <<  8 )         \
        | ( (uint64_t) ( data )[( offset )    ]       )         \
    )
#endif

/**
 * Put in memory a 64 bits unsigned integer in little-endian order.
 *
 * \param   n       64 bits unsigned integer to put in memory.
 * \param   data    Base address of the memory where to put the 64
 *                  bits unsigned integer in.
 * \param   offset  Offset from \p data where to put the least significant
 *                  byte of the 64 bits unsigned integer \p n.
 */
#ifndef MBEDTLS_PUT_UINT64_LE
#define MBEDTLS_PUT_UINT64_LE( n, data, offset )                \
{                                                               \
    ( data )[( offset )    ] = MBEDTLS_BYTE_0( n );             \
    ( data )[( offset ) + 1] = MBEDTLS_BYTE_1( n );             \
    ( data )[( offset ) + 2] = MBEDTLS_BYTE_2( n );             \
    ( data )[( offset ) + 3] = MBEDTLS_BYTE_3( n );             \
    ( data )[( offset ) + 4] = MBEDTLS_BYTE_4( n );             \
    ( data )[( offset ) + 5] = MBEDTLS_BYTE_5( n );             \
    ( data )[( offset ) + 6] = MBEDTLS_BYTE_6( n );             \
    ( data )[( offset ) + 7] = MBEDTLS_BYTE_7( n );             \
}
#endif

/* Fix MSVC C99 compatible issue
 *      MSVC support __func__ from visual studio 2015( 1900 )
 *      Use MSVC predefine macro to avoid name check fail.
 */
#if (defined(_MSC_VER) && ( _MSC_VER <= 1900 ))
#define /*no-check-names*/ __func__ __FUNCTION__
#endif

#endif /* MBEDTLS_LIBRARY_COMMON_H */
